There are various kinds of carbon-based materials whose properties differ greatly corresponding to bonding configurations of carbons. These carbon-based materials include new materials of which superior properties have been confirmed and that are expected to be widely used in the field of an electronic device, a hydrogen storage material, and the like, as in the case of a carbon nanotube and fullerene. There has been proposed a process for producing these new carbon-based materials easily and with good reproducibility (for example, JP 9(1997)-309713 A).
In the field of hydrogen absorption, a carbon-based material using amorphous carbon has been proposed. For example, JP 2001-106516 A discloses layer-structured amorphous carbon including carbon crystallites of hydrocarbon, as a material having a large hydrogen storage capacity per volume. JP 2002-28483 A discloses a reactant formed from amorphous carbon and an alkaline metal as a material that can occlude hydrogen easily at around room temperature.
JP 2001-261318 A discloses a multilayer film in which low hardness carbon films containing graphite clusters that have an average size of 2 nm or more, and high hardness carbon films containing graphite clusters that have an average size of 1 nm or less are laminated alternately. This multilayer film can be used as a coating film for various members that has improved wear resistance and frictional performance.